Puffer engines

The engines that are most commonly used in puffers are the p12 Schick engine, the p16 Coe ship, the p20 B-heptomino-based engine found in the space rake, and a related period-12 puffer engine. This period-12 B-heptomino-based engine is found in Gosper's total aperiodic pattern.

Puffers

The first known puffer, puffer 1, traveled orthogonally at c/2, and was found in early 1971. Cleaning up puffer output with the sparks of the standard spaceships allowed the creation versatile puffers of most periods which are multiples of 4. One method of creating very high period puffers is by having a long line of live cells supported on one side by a c/2 component. These are known as line puffers. Original stabilisations of line puffers yielded unstable results, which burn out after millions of generations. Since then, a much more resilient modification has been found. It is an open problem as to whether this line puffer is stable for all lengths.

Rakes

The first rake to be constructed was the space rake, which fired forward gliders at a period of 20. Since then many rake periods have been found, the smallest being that of backrake 1. Some adjustable period rakes have been created, but there is no known method of creating period x + 2n rakes.

Adjustable-period rakes

Adjustable-period rakes are generally composed of a period-8 blinker puffer and a fleet of standard spaceships. The trail of blinkers produced by the puffer form a fuse, which can be ignited by a pair of gliders to burn at a speed greater than c/2. This allows the spark to catch up with the puffer. This repeats periodically, the period of which can be increased by moving the spaceships outward.

Wickstretchers

There are several known c/2 orthogonal wickstretchers. The most simple wickstretcher of this speed stretches a period 6 wick from a stationary stabilizer. This wickstretcher can be widened with the zebra stripesagar bounded by the period 6 wick. This was the basis of halfmax, a spacefiller that fills half of the Life plane with zebra stripes. There is also a known incomplete wickstretcher which stretches a period 16 wick.

Spacefillers

The only known spacefillers stretch the zebra stripes agar at a speed of c/2 orthogonally in either three or all four cardinal directions on the Life plane. Examples of this include max and halfmax.

Guns

The three standard spaceships all have relatively simple glider syntheses, which makes the creation of c/2 orthogonal spaceship guns rather simple. Known glider synthesis techniques for these spaceships, however, only allow the creation of period 23 or higher spaceship streams. Many other c/2 spaceships also have known glider syntheses, which allows the creation of a variety of c/2 spaceship guns.